1. Field of the Invention
The present invention generally relates to key assemblies and, particularly, to a keypad assembly applied to a portable electronic device, such as mobile telephone, electronic notebook, and a portable electronic device with the same.
2. Description of Related Art
With the development of wireless communication and information processing technologies, portable electronic devices, such as mobile telephones and personal digital assistants (PDAs), are now in widespread use. These portable electronic devices enable consumers to enjoy high technology services, anytime and anywhere. A keypad assembly as an input terminal has been an indispensable member of a portable electronic device.
A typical keypad assembly is used for a portable electronic device including a printed circuit board therein. Several fixed contact points are formed on the printed circuit board and several dome switches respectively disposed above the fixed contact points. Referring to FIGS. 7 and 8, the keypad assembly 100 (i.e., the keypad), as illustrated, includes three keys 12, an elastic member 14, and a base 16. Three spaced blocks 162 protrude from an upper surface 164 of the base 16. Four cylindrical projections 166 extend from a lower surface 168 of the base 16. The elastic member 14 has three spaced rectangular through apertures 142 defined therein. In assembly, the fixing blocks 162 are respectively received in a corresponding through aperture 142 of the elastic member 14 so that the fixing blocks 162 are locked in the elastic member 14. The keys 12 are then respectively fixed on the fixing blocks 162 by means of a glue or another adhesive. Accordingly, the above key elements are assembled together. When the key 12 is pushed downward, the cylindrical projection 166 overcomes the elastic force from the dome switch so as to contact the fixed contact point, thereby generating a signal.
However, since miniaturization of the portable electronic device is desired, it would be helpful if the thickness of the elastic member 14 and the fixing blocks 162 could be reduced. This thickness reduction would, however, likely decrease the strength of the keypad assembly 100 and thus make the keypad assembly 100 more susceptible to breakage. In addition, since the contact area between the fixing blocks 162 and the elastic member 14 is reduced, the bonding force produced between the elastic member 14 and the fixing blocks 162 would likewise be reduced. As such, the keys 12 may be more prone to break away from the base 16 when the portable electronic device is dropped on the ground.
Therefore, a keypad assembly is desired in order to overcome the above-described problems.